The prior art describes a host of dye systems which can be used in the photographic industry to extend the spectral sensitivity of silver halide elements. A light-sensitive silver halide emulsion is spectrally sensitized when it is rendered more sensitive by addition of dyes which absorb certain portions of the spectrum. These dyes are described as sensitizers for both negative-working and positive-working (direct positive) silver halide systems. Certain combinations of dyes can be added to negative-working systems to cause a so-called "supersensitizing" effect. Supersensitization usually results in speed and spectral extension of the emulsion beyond that which might be predicted from a simple arithmetic addition of the individual effects produced by each dye alone. Supersensitization is an old phenomenon in the negative-working silver halide industry. A good review of this subject is found, for example, in Gilman et al, J. Photogr. Sci., Vol. 21, pages 53-70 (1973). Supersensitization of direct positive emulsions using dye pairs is also known in the prior art.